1. Field of the Invention
The present invention relates generally to a cassette tape recorder and more particularly to an automatic switch-off system when a tape forward winding or rewinding is completed.
2. Description of the Prior Art
There have already been designed various types of automatic switch-off systems in tape recorders. These may be divided into such types as an electric means for switching-off the state of tape running with an electro-magnet which is energized by electric signals generated by photoelectric or electric means of sensing completion of winding the tape; a mechanical means torque system wherein the overload in the tape rotating mechanism at the time of completion of tape winding is used as sensing signals; a mechanical differential system wherein the difference in the movements of capstan shaft and tape running coupling member is used as a sensing signal; and finally a combination of the mechanical sensing means and an electromagnet which switches off the system.
However in using electric means for a sensing member, it is necessary to specially design a part of the tape to be sensed and an electromagnet is necessary for converting the electric signals obtained by the sensing member into mechanical actions. The incorporation of the electromagnet makes the tape reproducer and recorder bulky and heavy.
Therefore, this sort of electric means and the above mentioned combined means are not suitable for a small, portable tape recorder. However, the above mentioned mechanical means is best suited for an automatic switch-off system in a small tape recorder due to simple construction, efficient high volume production, and compactness.